Cracks occurred in hexagon socket head bolts of ML20MnTiB cold heading steel wire.The microstructure,hardness and alloying element distribution of high strength bolt made of ML20MnTiB were analyzed by optical microscopy, scanning electron microscopy and Rockwell hardness respectively.The results show that the cracking cause are structural heterogenity and surface defects on the wire rod.
The transformation hot test for bar rolling line No.3 in SGIS was completed in January 2022. Due to the change of process and equipment, after the finished product was placed on the cooling bed, the rebar heads were bent, which seriously restricted the working capacity of the cooling bed and the efficiency of cold flying shears. Aiming at the bending phenomenon of the rebars on the cooling bed, a transformation plan was formulated based on the factors such as heating temperature, cooling after rolling, and multiple-length cutting, and after the transformation, the phenomenon of bending on the cooling bed was successfully improved.
建筑钢筋生产采用钒氮合金强化工艺,生产中抑制钒氮合金中氮化钒的氧化,对稳定建筑钢筋中氮含量和钢材性能至关重要.文章通过HRB500E钢转炉终点控制与钢中氮含量的相关性分析以及转炉正交试验,分析影响氮化钒氧化主要因素.加强转炉终点控制,严禁钢水过氧化,将转炉终点钢水活度氧控制在700 × 10-6以下,在转炉出钢后期加入钒氮合金,能有效控制氮化钒的氧化,提高钢种氮含量.
工业生产数字化、智能化的发展,给嵌入式工业设备带来更多的需求.原来只负责传输脉冲式指令反馈的现场总线,承载了大数据实时反馈,多线程事件同步、时序型应用数据交互等复杂功能,增加了现场总线应用协议的复杂度.在严格的实时性要求、有限的运算资源下,总线协议数据的处理方式成为关键,文章以协议数据中经常涉及的数据表查找方式的优化为研究对象,在TI Code Composer Studio通过XDS110仿真器连接TMS28388D开发环境下,分别利用树形查找、目录查找、散列查找和二分查找算法对通信协议数据表中的目标数据进行查找,并用时间复杂度对4种查找算法的性能作了对比,最终确定了二分查找和散列查找是诸多算法中的理想选择.
在冶炼过程中,需要依据亚铁含量来控制焦炭的供给量.在亚铁含量的检测中,传统的重铬酸钾滴定法需要较长的时间才能测得亚铁含量.文章使用Phen-HF-H2SO4为溶剂溶解试样,采用重铬酸钾滴定法对亚铁含量进行检测.结果表明:与传统的重铬酸钾滴定法相比,使用Phen-HF-H2SO4为溶剂能够降低溶样温度,提高检测的可重复性.
